Only honor T and D bits if E bit has not been encountered.

Fixes Silent Hill 2 hanging at movies.
jpd002 · Sep 12, 2024 · afa8564 · afa8564
1 parent b0f1fce
commit afa8564
Show file tree

Hide file tree

Showing 4 changed files with 24 additions and 8 deletions.
diff --git a/Source/BasicBlock.cpp b/Source/BasicBlock.cpp
@@ -261,7 +261,7 @@ void CBasicBlock::CompileEpilog(CMipsJitter* jitter, bool loopsOnItself)
 	jitter->BeginIf(Jitter::CONDITION_LE);
 	{
 		jitter->PushRel(offsetof(CMIPS, m_State.nHasException));
-		jitter->PushCst(MIPS_EXECUTION_STATUS_QUOTADONE);
+		jitter->PushCst(MIPS_EXCEPTION_STATUS_QUOTADONE);
 		jitter->Or();
 		jitter->PullRel(offsetof(CMIPS, m_State.nHasException));
 	}

diff --git a/Source/GenericMipsExecutor.h b/Source/GenericMipsExecutor.h
@@ -69,7 +69,7 @@ class CGenericMipsExecutor : public CMipsExecutor
 			auto block = m_blockLookup.FindBlockAt(address);
 			block->Execute();
 		}
-		m_context.m_State.nHasException &= ~MIPS_EXECUTION_STATUS_QUOTADONE;
+		m_context.m_State.nHasException &= ~MIPS_EXCEPTION_STATUS_QUOTADONE;
 #ifdef DEBUGGER_INCLUDED
 		if(m_context.m_State.nHasException == MIPS_EXCEPTION_BREAKPOINT)
 		{

diff --git a/Source/MIPS.h b/Source/MIPS.h
@@ -45,7 +45,11 @@ enum
 	MIPS_EXCEPTION_VU_DBIT,
 	MIPS_EXCEPTION_VU_TBIT,
 	MIPS_EXCEPTION_VU_EBIT,
+	MIPS_EXCEPTION_MAX, //Used to make sure we don't conflict with the QUOTADONE status
 };
+static_assert(MIPS_EXCEPTION_MAX <= 0x80);
+
+static constexpr uint32 MIPS_EXCEPTION_STATUS_QUOTADONE = 0x80;
 
 struct TLBENTRY
 {
@@ -55,8 +59,6 @@ struct TLBENTRY
 	uint32 pageMask;
 };
 
-#define MIPS_EXECUTION_STATUS_QUOTADONE 0x80
-
 struct MIPSSTATE
 {
 	uint32 nPC;

diff --git a/Source/ee/MA_VU_Upper.cpp b/Source/ee/MA_VU_Upper.cpp
@@ -30,16 +30,30 @@ void CMA_VU::CUpper::CompileInstruction(uint32 nAddress, CMipsJitter* codeGen, C
 
 	((this)->*(m_pOpVector[m_nOpcode & 0x3F]))();
 
+	auto setTDBitException = [&](uint32 exceptionValue) {
+		//Only set TD bit exception if there's no other outstanding
+		//exceptions (ie.: E bit). We could set a bit for every stop bit
+		//we encounter, but we assume that no game relies on multiple bits
+		//being set.
+		//This assumes that QUOTADONE is only set at the end
+		m_codeGen->PushRel(offsetof(CMIPS, m_State.nHasException));
+		m_codeGen->PushCst(0);
+		m_codeGen->BeginIf(Jitter::CONDITION_EQ);
+		{
+			m_codeGen->PushCst(exceptionValue);
+			m_codeGen->PullRel(offsetof(CMIPS, m_State.nHasException));
+		}
+		m_codeGen->EndIf();
+	};
+
 	if(m_nOpcode & VUShared::VU_UPPEROP_BIT_D)
 	{
-		m_codeGen->PushCst(MIPS_EXCEPTION_VU_DBIT);
-		m_codeGen->PullRel(offsetof(CMIPS, m_State.nHasException));
+		setTDBitException(MIPS_EXCEPTION_VU_DBIT);
 	}
 
 	if(m_nOpcode & VUShared::VU_UPPEROP_BIT_T)
 	{
-		m_codeGen->PushCst(MIPS_EXCEPTION_VU_TBIT);
-		m_codeGen->PullRel(offsetof(CMIPS, m_State.nHasException));
+		setTDBitException(MIPS_EXCEPTION_VU_TBIT);
 	}
 
 	if(m_nOpcode & VUShared::VU_UPPEROP_BIT_I)